The present invention relates to mobile devices, especially small portable mobile devices that can be carried in a pocket. It further relates to mobile devices that admit autonomous or external events to have a great importance to the user of the device. The invention encompasses all mobile phones, palmtop computers, personal digital assistants, etc. The events include incoming phone calls, incoming messages, connections to communication or data networks, alarms, warnings and reminders. When those kinds of events occur the devices change their internal state. Normally, a visual check of the device makes the internal state of the device clear to the user by a displayed information. Sometimes, a visual check is not possible or even unwanted.
EP publication 0 467 071 A2 discloses a subscriber terminal in a telecommunication system. A conventional alarm tone indicating an incoming call may be replaced with a vibration to be sensed by the user. A device implementing the vibration can be located within the casing of the subscriber terminal or it can be a separate device that is connected to the subscriber terminal through a wired or a wireless data transmission connection.
Publications WO 93/15590 and U.S. Pat. No. 5,696,497 disclose a radio transceiver that employs both silent and audible alarms. A silent alarm can be implemented by vibration, for instance. The radio transceiver informs the user of an incoming call using the silent alarm and if the user does not answer the call within a predetermined time, the radio transceiver gives an audible alarm using tones. The device implementing the vibration is located in the subscriber terminal. The radio transceiver can also automatically change the alarm mode employed from silent alarm alone to audible alarm when the radio transceiver is connected to an external power supply or a holder. The user can control the duration of the alarm and the periodic alternation of silent and audible alarms.
EP publication 0 688 125 A1 discloses a mobile station employing an automatic vibration alarm. A device implementing the vibration is located in a module separate from the mobile station, for instance in a battery of the mobile station. Apart from vibration, the silent alarm can be for example implemented with a light.
Computer games employ controllers by which attempts are made to model the game's onscreen virtual reality. By means of the mouse, it is possible to model the onscreen reality. The mouse can provide a tactile feedback. For instance, when the cursor clicks an onscreen button, the user feels a snap in the mouse that represents clicking. It is also possible to sense e.g. various surface materials with the mouse. If the computer display shows ice, the mouse simulates a sliding movement, especially the speed of movement when the cursor is passing over the ice, as compared with the cursor moving over sand shown on the screen. When moving over the sand, the mouse can also shake.
The above described tactile alarm modes inform of an incoming call and user interfaces attempting to model virtual reality by means of touch. Mobile telephones are also known which inform the user with an even vibration that he has selected a closing function, i.e. power switch-off, or an opening function, i.e. power switch-on. This represents a tactile version of keypad tones.